1. Technical Field
The present invention relates generally to cellular wireless communication networks; and more particularly to operations of a next generation mobile terminal that is roaming into a legacy wireless communication network.
2. Related Art
Cellular wireless networks include a xe2x80x9cnetwork infrastructurexe2x80x9d that facilitates wireless communications with mobile terminals operating within a respective service coverage area. The network infrastructure couples to other network to support communications, e.g., the Public Switched Telephone Network (PSTN), the Internet, etc. Wireless mobile terminals operating within a service coverage area of the network infrastructure wirelessly communicate with base stations of the network infrastructure. The network infrastructure routes the communications to another subscribing wireless units, to terminals coupled to the PSTN, to terminals coupled to the Internet, or to terminals coupled via another network to one of these networks.
Various wireless interface standards have been developed to standardize wireless communications between the mobile terminals and the network infrastructure. Wireless interface standards include, for example, the Advanced Mobile Phone Service (AMPS) standards, the Global System for Mobile communications (GSM) standards, the Code Division Multiple Access (CDMA) standards and the Time Division Multiple Access (TDMA) standards. Generations of these standards are generally referred to as first generation (1G), second generation (2G), third generation (3G), fourth generation (4G), etc. Each advancing generation of standards typically performs a greater number of services, supports a greater number of features, and provides better communication qualities. These operating standards may also be partially deployed from generation to generation, e.g., 2G to 2.5G.
Some partial generation wireless standard updates may be deployed using a legacy infrastructure. For example, a 2.5G network has been deployed using upgraded components of a 2G network. However, when moving from one generation to another generation, e.g., 2G to 3G, the network infrastructure must typically be rebuilt using new infrastructure components.
Network infrastructure replacement is both expensive and difficult to deploy. An additional problem resulting from the generational replacement of the network infrastructure relates to backward compatibility for subscribers. With 3G networks, for example, a subscriber subscribes to 3G services, which includes a suite of services. A 3G subscription may include, for example, circuit switched voice services for the subscriber""s 2G mobile terminal, packet switched voice service for the subscriber""s 3G packet switched mobile terminal, packet data services for the subscriber""s personal data assistant, and packet data services for the subscriber""s notebook computer, among other services. However, each of the subscriber""s wireless devices may not be compatible with the 3G infrastructures. Further, operations of the 3G network must correspond to particular services being employed, i.e., the network must operate differently for different requested services.
In a typical next generation 3G infrastructure, legacy (2G) terminal support will be provided. When 3G systems are deployed, 3G mobile terminals will be placed into service. In such cases, the 3G infrastructures will support the 3G services for the 3G mobile terminals as they operate within the respective service areas. However, the 3G mobile terminals must also be serviced while roaming into legacy 2G wireless networks. Thus backward compatibility issues arise that have not heretofore been addressed.
Further, 3G wireless devices may be placed in service within a legacy network, and thus will be limited in their operation to certain services. If such a 3G wireless device roams from its home service area into an area that supports all 3G packet switched services, the 3G wireless device should not be allowed to receive packet switched services to which it does not subscribe. In such case, the visited network must prevent delivery of these services.
Thus, there is a need in the art for a system and method that may be employed to support both legacy mobile terminals and next generation mobile terminals within next generation wireless communication systems and further to properly service next generation terminals within next generation networks that have subscribed within legacy networks.
Thus, to overcome the shortcomings of the prior systems and methods, among other shortcomings, a method of the present invention supports operation of mobile terminal having a subscription in a packet switched (3G) wireless network within a legacy (2G) wireless network. Initially, when the 3G mobile terminal roams into the service area of the legacy network, the mobile terminal sends an attach request to a support node of the legacy wireless network. The legacy wireless network then authenticates the mobile terminal.
Next, the support node of the legacy wireless network interacts with the packet switched wireless network to receive the mobile terminal""s subscriber data. The home subscriber service function of the packet switched wireless network then interacts with a prior support node to cancel the wireless terminals prior location. The support node of the legacy wireless network next requests a visitor location register of the legacy wireless network to register the mobile terminal. The visitor location register of the legacy wireless network then interacts with the packet switched wireless network to register the mobile terminal within the legacy wireless network.
The visitor location register of the legacy wireless network next acknowledges to the support node that the mobile terminal has been registered within the legacy wireless network. Finally, the support node of the legacy wireless network acknowledges the attach request to the mobile terminal. By interacting with the packet switched wireless network in this manner, the legacy network may not only provide service but determine the level at which service should be performed. These operations are a requirement for proper servicing by the legacy wireless network of the mobile terminal.
In its interaction with the packet switched wireless network to receive the mobile terminal""s subscriber data, the support node of the legacy wireless network sends an update location message to a home subscriber service function of the packet switched wireless network. The home subscriber service function of the packet switched wireless network then interacts with the support node of the legacy wireless network to download subscriber data to the support node of the legacy wireless network. With this interaction complete, the home subscriber service function of the packet switched wireless network sends an update location acknowledge message to the support node of the legacy wireless network.
According to one embodiment of these operations, the visitor location register of the legacy wireless network sends a message via the roaming signaling gateway function of the packet switched wireless network to the home subscriber service function of the packet switched wireless network to request an update of the mobile terminal""s location. The visitor location register then communicates with the home subscriber service function of the packet switched wireless network via the roaming signaling gateway function of the packet switched wireless network to receive subscriber data for the mobile terminal. With these operations completed, the home subscriber service function of the packet switched wireless network sends a message to the visitor location register of the legacy network via the roaming signaling gateway function of the packet switched wireless network to acknowledge the update of the mobile terminal""s location.
According to one embodiment of the mobile terminal, the mobile terminal supports both legacy wireless network operations and packet switched wireless network operations. However, with another embodiment of the mobile terminal, the mobile terminal supports only legacy wireless network operations.
According to an additional operation for the methods described above, a packet data context for the mobile terminal within the legacy wireless network is created. Moreover, after the registration operations have been completed, the mobile terminal may originate a call within the legacy wireless network. Further, the legacy wireless network may terminate a call to the mobile terminal.
In terminating a call to the mobile terminal, the legacy wireless network receives a call termination request from a coupled network at a gateway switch. The gateway switch then sends a routing information request message to the roaming signaling gateway function of the packet switched wireless network. The roaming signaling gateway function of the packet switched wireless network next interacts with the home subscriber service function of the packet switched wireless network to determine a serving switch of the legacy wireless network.
As a further operation, the roaming signaling gateway function of the packet switched wireless network interacts with the serving switch of the legacy wireless network to determine a roaming number for the mobile terminal. The roaming signaling gateway function of the packet switched wireless network forwards the roaming number for the mobile terminal to the originating switch. Finally, the originating switch terminates the call to the mobile terminal via the serving switch.
According to a second operation of the present invention, a packet switched wireless network services packet switched operations for a packet switched mobile terminal. In servicing the communication, a servicing support node of the packet switched wireless network receives an attach request message from the mobile terminal. In response, the packet switched wireless network authenticates the mobile terminal. Next, the support node of the packet switched wireless network interacts with a home subscriber service function of the packet switched wireless network to receive the mobile terminal""s subscriber data. The support node of the packet switched wireless network then interacts with a home subscriber service function of the packet switched wireless network to update the mobile terminal""s location. The support node of the packet switched wireless network responds to the mobile terminal with an attach accept message.
The mobile terminal then sends an application registration request message via the support node to a call state control function of the packet switched wireless network, wherein the application request message seeks to register a voice over internet protocol application supported by the mobile terminal. The call state control function of the packet switched wireless network next interacts with the home subscriber service function of the packet switched wireless network to register the application. Finally, the call state control function of the packet switched wireless network sends a registration confirmation message to the mobile terminal.
After these operations have been completed, the mobile terminal may originated a packet switched call and the packet switched network will service the call. Further, the packet switched wireless network may receive a packet switched call by the packet switched wireless network and terminate the packet switched call to the mobile terminal via the packet switched wireless network.
In terminating the packet switched call to the mobile terminal via the packet switched wireless network, a home call state control function of the packet switched wireless network receives a call setup message. The home call state control function of the packet switched wireless network then interacts with the home subscriber service function of the packet switched wireless network to determine a serving call state control function of the packet switched wireless network. Next, the home call state control function of the packet switched wireless network forwarding the call setup message to the serving call state control function of the packet switched wireless network. Finally, the serving call state control function of the packet switched wireless network operates to initiate call termination to the mobile terminal.
Moreover, other aspects of the present invention will become apparent with further reference to the drawings and specification, which follow.